College of Food Science, Guangdong Pharmaceutical University, Zhongshan, Guangdong 528458, China; Nanfang Hospital Baiyun Branch, Southern Medical University, Guangzhou, Guangdong 510600, China.
College of Food Science, Guangdong Pharmaceutical University, Zhongshan, Guangdong 528458, China.
J Microbiol Methods. 2024 Sep;224:107008. doi: 10.1016/j.mimet.2024.107008. Epub 2024 Aug 3.
Proteus mirabilis is a predominant species in cases of food poisoning associated with meat products and is also an opportunistic pathogen causing numerous infections in humans. This study aimed to differentiate P. mirabilis isolates using intergenic region polymorphism analysis (IRPA). The IRPA typing scheme was developed to amplify polymorphic fragments in intergenic regions (IGRs). The presence, absence, or size change of amplified products were identified and utilized as genetic markers for rapid differentiation of strains. A total of 75 P. mirabilis isolates were isolated from 63 fresh poultry and pork samples were subtyped using the IRPA and ERIC-PCR methods, and their antibiotic resistance profiles were tested. The majority of P. mirabilis isolates showed resistance to tetracycline (85.3%), doxycycline (93.3%), chloramphenicol (82.7%), streptomycin (92.0%), spectinomycin (80.0%), trimethoprim (97.3%); trimethoprim-sulfalleth (82.7%), and erythromycin (100.0%). In contrast, resistance rates to ceftriaxon, cefoxitin, cefepime, and cefotaxim were lower at only 17.3%, 5.3%, 6.7%, and 13.3%, respectively, among P. mirabilis isolates. Eleven loci were selected for analysis of the genetic diversity of 75 P. mirabilis isolates. A combination of 4 loci was determined as the optimal combination. The results compared to those obtained using ERIC-PCR for the same isolates. The Simpson's index of diversity was 0.999 for IRPA and 0.923 for ERIC-PCR, indicating that IRPA has a higher discriminatory power than ERIC-PCR. The concordance between IRPA and ERIC-PCR methods was low, primarily because IRPA classified isolates from the same ERIC cluster into separate clusters due to its high resolution. The IRPA method presented in this study offers a rapid, simple, reproducible, and economical approach for genotyping P. mirabilis.
奇异变形杆菌是与肉制品相关的食物中毒的主要病原体，也是引起人类多种感染的机会性病原体。本研究旨在使用种间区多态性分析（IRPA）对奇异变形杆菌分离株进行区分。IRPA 分型方案是为了扩增种间区（IGR）中的多态性片段而开发的。通过鉴定扩增产物的存在、缺失或大小变化，将其用作快速区分菌株的遗传标记。从 63 份新鲜禽肉和猪肉样本中分离出 75 株奇异变形杆菌，采用 IRPA 和 ERIC-PCR 方法对其进行亚型分型，并检测其抗生素耐药谱。大多数奇异变形杆菌分离株对四环素（85.3%）、强力霉素（93.3%）、氯霉素（82.7%）、链霉素（92.0%）、壮观霉素（80.0%）、甲氧苄啶（97.3%）；磺胺甲噁唑/甲氧苄啶（82.7%）和红霉素（100.0%）表现出耐药性。相比之下，奇异变形杆菌分离株对头孢曲松、头孢西丁、头孢吡肟和头孢噻肟的耐药率仅为 17.3%、5.3%、6.7%和 13.3%。选择 11 个基因座分析 75 株奇异变形杆菌分离株的遗传多样性。确定 4 个基因座的组合为最佳组合。与对同一分离株进行的 ERIC-PCR 结果进行比较。IRPA 的 Simpson 多样性指数为 0.999，ERIC-PCR 为 0.923，表明 IRPA 的分辨率高于 ERIC-PCR。IRPA 与 ERIC-PCR 方法的一致性较低，主要是因为 IRPA 由于分辨率高，将来自同一 ERIC 簇的分离株分类到不同的簇中。本研究中提出的 IRPA 方法为奇异变形杆菌的基因分型提供了一种快速、简单、可重复和经济的方法。
